The 2007 email from Jobs to Schmidt was disclosed on Friday in the course of civil litigation against Apple Inc, Google Inc and five other technology companies. The proposed class action, brought by five software engineers, accuses the companies of conspiring to keep employee compensation low by eliminating competition for skilled labor.

In 2010, Google, Apple, Adobe Systems Inc, Intel Corp, Intuit Inc and Walt Disney Co's Pixar unit agreed to a settlement of a U.S. Justice Department probe that bars them from agreeing to refrain from poaching each other's employees.

According to an unredacted court filing made public in the civil litigation on Friday, the now-deceased Jobs emailed Schmidt in March 2007 about an attempt by a Google employee to recruit an Apple engineer. Schmidt was also an Apple board member at the time.

I would be very pleased if your recruiting department would stop doing this, Jobs wrote.

Schmidt forwarded Job's email onto other, undisclosed recipients.

Can you get this stopped and let me know why this is happening? Schmidt wrote.

Google's staffing director responded that the employee who contacted the Apple engineer will be terminated within the hour.

He added: Please extend my apologies as appropriate to Steve Jobs.

Google spokeswoman Niki Fenwick said on Friday the company, has always actively and aggressively recruited top talent.

Apple representatives did not immediately respond to requests for comment.

The tech defendants have asked a U.S. judge in San Jose, California to quickly dismiss the civil lawsuit, arguing that the companies engaged in bilateral anti-poaching deals to protect collaboration. The companies did not participate in an overarching conspiracy, they argued in filings.

But at a court hearing this week, U.S. District Judge Lucy Koh said the civil lawsuit will proceed, although it may be split up into multiple potential class actions.

Among the revelations stemming from the civil litigation is a 2007 note from Palm's chief executive to Apple's Steve Jobs, saying that an anti-poaching agreement would be likely illegal.

The latest court filing also refers to a 2007 note from Intel chief executive Paul Otellini discussing that company's agreement with Google.

Let me clarify. We have nothing signed, Otellini wrote. We have a handshake 'no recruit' between eric and myself. I would not like this broadly known.

Intel representative Sumner Lemon said on Friday the company, disagrees with the allegations contained in the private litigation related to recruiting practices and plans to conduct a vigorous defense.

The case in U.S. District Court, Northern District of California is In Re: High-Tech Employee Antitrust Litigation, 11-cv-2509.